One Week Friends (Japanese: 一週間フレンズ。,Hepburn: Isshūkan Furenzu.) is a manga series by Matcha Hazuki. It was serialized in Square Enix's Gangan Joker magazine between January 21, 2012 and January 22, 2015. It was first published as a one-shot manga in the magazine's September 2011 issue. The series has since been collected in seven tankōbon volumes. An anime television series adaptation by Brain's Base aired between April 6 and June 22, 2014. Sentai Filmworks licensed the rights to the show in North America and by Madman Entertainment in Australia and New Zealand. A live-action film of the same name was released in February 2017.

Contents

High schooler Yūki Hase notices that his classmate Kaori Fujimiya is always alone and seemingly has no friends. After approaching her and becoming better acquainted, Kaori reveals that every Monday she loses all memory of her friends. Despite learning this, Yūki endeavors to befriend her anew every week.

Yūki is a second year high school student who develops an interest in an isolated classmate, Kaori Fujimiya. Despite Kaori forgetting about him every week, he never ceases working hard to earn her smile. He's weak in mathematics.

Kaori is Yūki's classmate who chooses to not make friends as she loses her memories concerning friends at the beginning of every week. She used to be popular in school, but was in a car accident that gave her a severe case of anterograde amnesia. She decides to keep a diary after Yūki suggests that she record her experiences. This helps her to become more and more familiar with Yūki, to the point of just barely remembering him. She had made a promise to meet up with her childhood friend, Hajime Kujō, but was unable to do so because of the accident. Her mother suggests that to an extent, she may be repressing her own memories. She is quite good in mathematics as compared to Yūki, and often helps him with his studies.

Saki is a clumsy and forgetful girl in their class who used to be Shōgo's primary school classmate. She used to be bullied due to her small stature in primary school, and has since depended on others for all matters.

Hajime is a student who transfers in during the second semester and who was Kaori's primary school classmate. He and Kaori promised to meet in the park the day before he transferred to Hokkaido, but Kaori did not show up due to her accident. His family has strict demands on him, to the point where he isn't allowed to buy games.

One Week Friends began as a one-shot manga by Matcha Hazuki and was first published in Gangan Joker's September 2011 issue. A full serialization later followed in Square Enix's Gangan Joker from January 21, 2012.[1] After spanning three years, the series came to an end in the February 2015 issue of Gangan Joker which was published in Japan on January 22, 2015.[2] Despite the end of the serialization, a special chapter will later be included in the magazine's May 2015 issue when it is published on April 22, 2015.[3] The chapters was collected into a total of seven tankōbon volumes, the first of which was released on June 22, 2012.[4] The final volume was released on April 22, 2015.[5][6][7]

An anime television series adaptation by Brain's Base began airing on April 6, 2014.[13] The opening theme is "Niji no Kakera" (虹のかけら, lit. "Fragments of a Rainbow"), sung by Natsumi Kon, with lyrics and composition by Ai Kawashima.[14] The ending theme is a cover of Sukima Switch's 2004 single "Kanade" (奏（かなで）, lit. "Symphony") sung by Sora Amamiya, the voice actress of female protagonist, Kaori Fujimiya. The anime has been licensed by Sentai Filmworks in North America.[15]

Carl Kimlinger of Anime News Network published a positive review of the complete anime series.[17] He wrote that the premise can push its dramatic moments a little too far and almost nothing happens throughout the first half of the series. Regardless, Kimlinger praised the plot's character development, saying that it saves the first half with its progression through little events; he added that the dramatic scenes are nicely underplayed to help viewers care for the characters. Kimlinger wrote that Brain's Base and director Tarou Iwasaki provide the series with a style that's perfect, calling the minimalist backgrounds evocative with the right mood and the character animations superb, saying "that makes the show what it is: a sleeper delight, plain and simple."[17]

As of March 2, 2016, the manga had sold over 1 million copies in Japan.[18]